Implement release hitch for tractors



April 6, 1954 R. .J. ALTGELT ETAL IMPLEMENT RELEASE HITCH FOR TRACTORS Filed Aug. 25, 1951 INVENTORS J'AATGEZT BY 40mm c 4/4/0525 ATTO/P/VEV Patented Apr. 6, 195

IMPLEMENT RELEASE HITCH FOR TRACTORS Rudolph J. Altgelt, South C. Lindgren, Berkley, Mich., assignors, by mesne assignments, to Ford Motor Company, Dearborn, MiclL, a corporation of Delaware Application August 23, 1951, Serial N 0. 243,256

6 Claims. 1

This invention relates to an overload release hitch for attaching trailed implements to tractors.

With modern high powered, high speed tractors towin trailed implements and particularly ground working implements, it is quite essential that provision be made for instant release of the implement in the event that the implement strikes a relatively immovable and unyielding object such as a stone or a stump when working in the ground. It is quite apparent that if the implement is not immediately released when the obstruction is encountered by the implement,

serious damage can be done to either the implement or the tractor and in some instances bodily harm to the tractor operator.

It is, therefore, an object of this invention to provide an improved overload release device for implements to permit rapid release of the implement from the tractor in the event an obstruction is encountered by the implement.

Another object of this invention is to provide an improved overload implement release device which provides not only for instantaneous release of the implement from the tractor upon encountering a relatively immovable object but one which can be readily and conveniently reconnected to the implement.

The specific nature of this invention, as well as other objects and advantages thereof, will become apparent to those skilled in th art from the following detailed description, taken in conjunction with the one sheet of drawings on which, by way of preferred example only, is illustrated one embodiment of this invention.

On the drawings:

Figure 1 is a side view of the overload release mechanism shown in the locked position.

Figure 2 is a view similar to Figure 1 but showing th lock member in the released position.

Figure 3 is a plan view of Figure 2.

Figure 4 is an enlarged detail side view of the lower end portion of the latch.

Figure 5 is a view showing the right hand face of Figure 4.

Figure 6 is an enlarged detail rear view of the latch tip portion.

Figure 7 is a side view of Figure 6.

As shown on the drawings:

In Figure 1 there is shown, in assembled relation, an improved quick release hitch constructed in accordance with this invention. The hitch shown in Figure 1 comprises a bracket I0 consisting of a bottom plate Illa and a pair of laterally spaced Plate-like uprights lllb and I00, re-

Bend, Ind., and Arnold spectively welded to the forward edge of bottom plate Illa and to the center of such plate. Bracket Ill surrounds a tractor drawbar II. The uprights lllb and Ida respectively snugly engage the adjacent sides of drawbar II with bottom plate I Ila contacting the underside of drawbar II. A bolt l2 secures bottom plate Illa in a selected transverse position on drawbar II, as is usual there being a plurality of laterally spaced bolt holes Ila in drawbar II, any one of which may be conveniently aligned with a suitable vertical aperture in bottom plate Illa by simply sliding bracket Ill along drawbar II until proper register of the desired holes is effected. Bottom plate Illa is tapered rearwardly, as shown in Figure 3, from the rear edge of the upright plate Iflc to define a substantially triangular shaped arm portion llld. The extreme rear end of the arm portion Illd of plate Illa has a downwardly and rearwardly inclined surface Ille for a purpose to be later explained. The uprights Illb and lllc are respectively provided with aligned, transverse slots Ill) and lllg. Slot I0), however, tapers forwardly, as best shown in Figure 3, for a purpose to be presently described.

A latch carrier I3 is provided to rotatably support a latch I l to be later described. Latch carrier I3 has a rectangular body portion l3a which slidably fits within the vertical slots l0) and log respectively provided in upright plates lllb and Illc. A tapered shoulder I3?) is provided on the forward end of the rectangular portion I3a of latch carrier I3 which cooperates with the correspondingly shaped aperture lllf to act as a stop. The portion of latch carrier I3 projecting rearwardly from the upright plate Illc is of enlarged rectangular configuration and defines a head portion I30. The head portion I30 is bifurcated by a vertical slot H12 in which is inserted the latch I I.

Latch I4 is a two piece member comprising a substantially bar-like lever portion I la and a tip portion Mb. The lever portion I la of latch I4 is inserted within the slot I 3d defined by the bifurcated head portion I3c of latch carrier I3. Suitable aligned transverse holes are respectively provided in the end of head portion I30 and in the lever portion Ila of lever It to permit the insertion of a transverse pin IE to pivotally mount lever portion I la to the latch carrier IS. The tip portion I 4b is hingedly connected to the lever portion Ila and in its preferred form has a centrally disposed semicircular lug Me which cooperates in hinged relationship with a corresponding arcuately shaped recess l ld provided in the lever portion Ma. The lower end of lever portion Ma is thus substantially bifurcated by the recess Md thereby defining a pair of laterally spaced end portions Me having circularly shaped perimeters, as best shown in Figures 2 and 4. The circular .end portions Me fit within circularly formed cuts M) respectively provided in tip portion Mb on each side of the circular 111% Me. Lug Me and the circular ends Me of lever portion Ma are respectively axially apertured to permit the insertion of a pin Mg to pivotally secure the tip portion Mb to the end of the lever portion Ma. It will be noted that the pin Mg is located a substantial distance rearwardly of pin I5 and at the top of the tip portion Mb for a reason to presently appear.

A cylindrical boss Mn is provided on one side of arcuate lug Me so that when the tip portion Mb of latch M is assembled to the lever portion Ma, a recess Ms will be defined adjacent the right hand end portion Me of lever Ma, as best shown in Figure 5. A torsion spring Ma surrounds pin Mg and lies within the recess Ms. Spring M7 has its ends respectively bearing against the rear end surfaces of lever member Ma and the tip portion Mb to bias such tip portion in a clockwise direction, as best shown in Figure 4. The tip portion Mb has a shoulder Mk which normally abuts a corresponding shoulder Mm provided on the lever portion Ma to arrest clockwise rotary movement of such tip beyond such point. The tip portion Mb has a rounded lower end Mn blending with an upwardly sloped front surface Mp. It should be noted that when tip portion Mb lies in its normal position with shoulders Mk and Mm abutting, the length of latch M exceeds the vertical spacing between bracket plate IOa and latch carrier I3.

The upper end of lever portion Ma is transversely apertured and a rod-like link has its hook shaped rear end 25a pivotally secured within the transverse aperture. Link 25 extends forwardly to within the vicinity of the tractor seat (not shown) where it may be conveniently grasped by the tractor operator to operate the latch M as will be presently described.

Latch carrier I3 has a rod-like spring guide I3d integrally joined to the forward shoulder I3b provided on such latch carrier. A spring l6 surrounds spring guide I3d and the rear end of such spring abuts the forward face of the upright plate lb. The forward end of rod guide I3d. is threaded, as shown at I39, and a pair of nuts II are threaded onto such threaded end to adjustably preload spring I6. Thus, spring I6 normally biases latch carrier I3 forwardly or to the left, as shown in Figure 1, so that shoulder I3b is fully engaged in slot Ilif and thereby acts as a stop.

In Figures 1, 2 and 3 there is shown the forward portion of an implement frame I8. Such frame has a depending bracket I9 which is secured by a pair of bolts 20 to the leading edge of frame I8 in depending relationship. A ring 2| is suitably secured to the lower end portion of bracket I9, as by a transverse bolt 2Ia.

The above described hitch is conveniently connected to ring 2| by simply backing up the tractor so that the ring 2| passes between the rearwardly projecting latch carrier I3 and bottom plate Illa. The sloped end surface We provided on the rear end of plate Illa facilitates the insertion of ring 2| between the aforementioned two members. In this operation, latch M is rotated in a clockwise direction by the operator by a rearward thrust on link 25 to position the latch within the slot |3d of carrier I3 to permit the ring 2| to enter the opening defined by the latch carrier and arm Illa. The tip portion Mb of latch M pivots about its hinge pin Mg as latch M is moved in a clockwise direction to clear bracket plate Illa since, as mentioned above, the distance between the axis of pin I5 and the rounded end Mn of tip portion Mb is greater than the distance from the axis of pin I5 to the upper surface of bracket plate Ma. The tractor is backed rearwardly until the forward edge of ring 2| contacts the rear face of upright plate IIlc whereupon latch M is rotated in a counterclockwise direction by the operator pulling the link 25 until such latch assumes the position shown in Figure 1 with the rounded end Mn of tip Mb in contact with plate Illa.

When the tractor is started, the ring 2| will then contact the forward surface of tip Mb. However, latch M cannot rotate counterclockwise because of the engagement of rounded end Mn with plate Illa, and abutment of stop surfaces MR: and Mm. Furthermore, due to the location of pin Mg rearwardly of pin [5 and the fact that the rearward force imparted to tip Mb by ring 2| is below and forwardly of pin Mg, the upward component of force on tip Mb will thus act to effectively retain tip Mb in the position shown in Figure 1. Hence, the implement will be towed behind the tractor. In the event the implement strikes an obstruction in the ground so that its movement is arrested, or for any other reason the draft is increased beyond a safe point, the ring 2| will then force the carrier I3 to move rearwardly compressing spring I6. Carrier I3 will move rearwardly until the rounded end Mn of latch M clears the end of plate Illa whereupon latch M will be free to pivot in a counterclockwise direction to release the ring 2| from the hitch II).

To reattach the implement to hitch I0, it is merely necessary for the operator to rotate latch M in a clockwise direction, as previously described, to bring the tip portion Mb up into the slot I3d, in the head |3c of latch .carrier I3 whereupon the tractor is backed toward the implement so that ring 2| can pass between the opening defined by latch carrier I3 and plate Illa and latch M then re-engaged in the same manner as previously described.

In the event it is desired to change implements or to free the implement being towed behind the tractor, all that is necessary to do is to stop the tractor and back it up until ring 2| contacts the rear surface of the upright plate member I00. Latch M is then rotated in a clockwise direction to rotate tip Mb out of ring 2| into slot I3d whereupon the tractor may be moved forward, leaving the implement behind.

From the foregoing description it is clearly apparent that there is here provided a relatively simple yet positive overload release hitch for connecting implements to a tractor which will positively release the implement to avoid damage to either the implement or the tractor if such implement encounters an obstruction. This hitch may also be manually released from the tractor seat to conveniently permit other implements to be attached. It is also readily apparent that the leading of the hitch may be conveniently varied by adjustment of nuts I! to permit overload re lease of the hitch at any selected draft force.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the i wise than necessitated by said latch into engagement with said arm portion behind said connecting device, thereby connecting the implement to said second member, and resilient means opposing rearward move ment of said second member relative to said first member, whereby said latch will be pulled 01f said arm portion to release said connecting device upon the occurrence of a predetermined draft load.

2. An overload release hitch for connecting a trailed device to a tractor device, comprising a first member adapted for attachment to one of said devices and having a longitudinally extending arm portion, a second member mounted for longitudinal movement relative to said first member in the line of draft,

rence of a predetermined draft load.

3. An overload release hitch for connecting an for attachment to the implement and receivable in said opening, a two piece latch comprising a lever portion and a tip portion tating said lever portion to move said tip portion into engagement with said arm portion behind said connecting device, abutment means limiting pivotal movement of said tip portion in the one direction relative to said lever portion which would permit said tip portion to move out of engagement with said arm portion, thereby connecting the implement to said second member, and resilient means opposing rearward movement of said second member relative to said first member, whereby said latch will be pulled off said arm portion to release said connecting device upon the occurrence of a predetermined draft load.

4. An overload release hitch for connecting an implement to a tractor, comprising a first member adapted for attachment to the tractor and having a rearwardly extending arm portion, a

tion to define an opening therebetween, a connecting device adapted for attachment to the implement and receivable in said opening, a two piece latch comprising a lever portion and a tip portion hingedly connected to said lever portion,

gagement with said arm portion behind said connecting device, abutment means limiting pivotal movement of said tip portion in the one direction relative to said vice upon the occurrence of a predetermined draft load.

5. An overload release hitch for connecting an implement to a tractor, comprising a first member adapted for attachment to the tractor and having a rearwardly extending arm portion, a member mounted for movement relative first member in the line of draft, said second member being spaced from said arm portion to define an opening therebetween, a connecting device adapted for attachment to the imand receivable in said opening, a two greater over-all length than the width of said opening, and manually operable means for pivoting said lever portion to position said tip portion behind said connecting device and in engagement with said arm portion, thereby connecting said second member to the implement and resilient means opposing rearward movement of said sec-- ond member relative to said first member, whereby said latch Will be pulled off said arm portion to release said connecting device upon the occurrenoe of a predetermined draft load.

6. An overload release hitch for connecting an implement to a tractor, comprising a first member adapted for attachment to the tractor and having a rearwardly extending arm portion, a

tion to define an opening therebetween, a connecting device adapted for attachment to the implement and receivable in said opening, a two piece latch comprising a lever portion and a tip portion hingedly connected to said lever portion, means for pivotally mounting said lever portion on said second member, said lever portion and said tip portion having cooperating stop shoulders limiting relative pivotal movement in one direction, and spring means normally biasing said tip portion in a direction to yieldingly maintain said stop shoulders in abutment, said latch having a greater over-all length than the width of said opening, manually operable means for pivoting said lever portion to position said tip portion behind said connecting device and in engagement with said arm portion, thereby connecting said second member to the implement. and resilient means opposing rearward movement 0 of said second member relative to said first member, whereby said latch will be pulled off said arm portion to release said connecting device upon the occurrence of a predetermined draft load.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 15 1,323,634 Kagay Dec. 2, 1 19 

